20553252121 has 4 divisors (see below), whose sum is σ = 20597836644. Its totient is φ = 20508667600.

The previous prime is 20553252107. The next prime is 20553252143. The reversal of 20553252121 is 12125235502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6571372096 + 13981880025 = 81064^2 + 118245^2 .

It is a cyclic number.

It is not a de Polignac number, because 20553252121 - 2⁵ = 20553252089 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20553252121.

It is not an unprimeable number, because it can be changed into a prime (20553252721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22291570 + ... + 22292491.

It is an arithmetic number, because the mean of its divisors is an integer number (5149459161).

Almost surely, 2^20553252121 is an apocalyptic number.

It is an amenable number.

20553252121 is a deficient number, since it is larger than the sum of its proper divisors (44584523).

20553252121 is an equidigital number, since it uses as much as digits as its factorization.

20553252121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44584522.

The product of its (nonzero) digits is 6000, while the sum is 28.

Adding to 20553252121 its reverse (12125235502), we get a palindrome (32678487623).

The spelling of 20553252121 in words is "twenty billion, five hundred fifty-three million, two hundred fifty-two thousand, one hundred twenty-one".